The high resolution imaging science experiment (HiRISE) on the Mars Orbiter gives astronomers a view of the sediment deposits leftover from the lakes that once existed on Mars.
Astronomers believe Holden Crater was once filled by at least two different lakes. Now all that remains are the relatively light-toned sediments deposited in those lakes, as seen in this observation from NASA’s Mars Reconnaissance Orbiter.
Each layer represents a different point in time and perhaps a changing environment for Martian life, if it existed. The elongated ridges with sharp crests are sand dunes.
The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. The original image scale is 25.9 centimeters (10.2 inches) per pixel (with 1 x 1 binning); objects on the order of 78 centimeters (30.7 inches) across are resolved. North is up.
Source: NASA/JPL-Caltech/Univ. of Arizona